BG Chap 11 - Arjuna's description of the immeasurable form

The Lord is the supreme Brahman, the primal objective. He is the ultimate resting place of everything in this universe. He is inexhaustible, the protector of eternal religion spoken in the Vedas, and the oldest. The Lord is known by the strivers of liberation as Brahman. Being submerged in an ocean of the rasa of great astonishment, Arjuna repeats what he said before that the Lord is without beginning, middle or end. Repetition of statements two or three times due to joy, astonishment or kindness is not a fault. Arjuna saw the Lord having numberless arms, with the sun and moon for his eyes, and with a mouth of blazing fire, burning the universe. The eyes of the Lord are pleasing like the moon to the devas, who are obedient to the Lord, and harsh like the sun to the demons who disobey Him. The Lord had infinite vīrya or potency. This infers all the six opulences: vīrya (power), yaśas (fame), Śrī (beauty), jñāna (knowledge), vairāgya (detachment) and aiśvarya (riches).

It is understood that now, for seeing the war, the devas, asuras, Gandharvas, Kinnaras and others who were friendly or neutral had gathered. Not only Arjuna was given celestial eyes. They also were given celestial eyes by the Lord to see this form. If only Arjuna could see that form, it would have been like a sleeping person seeing chariots or other objects in a dream, while others could not see them. The Lord made this display so that many others could bear witness to His powers.